| Message ID | 20190725231931.24073-1-mcroce@redhat.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] mvpp2: refactor MTU change code | expand |
Hi Matteo, On Fri, Jul 26, 2019 at 01:19:31AM +0200, Matteo Croce wrote: > The MTU change code can call napi_disable() with the device already down, > leading to a deadlock. Also, lot of code is duplicated unnecessarily. > > Rework mvpp2_change_mtu() to avoid the deadlock and remove duplicated code. > > Signed-off-by: Matteo Croce <mcroce@redhat.com> As this is a fix sent to net, you could add a Fixes: tag. Otherwise this looks good, Acked-by: Antoine Tenart <antoine.tenart@bootlin.com> Thanks! Antoine > --- > .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 41 ++++++------------- > 1 file changed, 13 insertions(+), 28 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > index 2f7286bd203b..60eb98f99571 100644 > --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > @@ -3612,6 +3612,7 @@ static int mvpp2_set_mac_address(struct net_device *dev, void *p) > static int mvpp2_change_mtu(struct net_device *dev, int mtu) > { > struct mvpp2_port *port = netdev_priv(dev); > + bool running = netif_running(dev); > int err; > > if (!IS_ALIGNED(MVPP2_RX_PKT_SIZE(mtu), 8)) { > @@ -3620,40 +3621,24 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu) > mtu = ALIGN(MVPP2_RX_PKT_SIZE(mtu), 8); > } > > - if (!netif_running(dev)) { > - err = mvpp2_bm_update_mtu(dev, mtu); > - if (!err) { > - port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); > - return 0; > - } > - > - /* Reconfigure BM to the original MTU */ > - err = mvpp2_bm_update_mtu(dev, dev->mtu); > - if (err) > - goto log_error; > - } > - > - mvpp2_stop_dev(port); > + if (running) > + mvpp2_stop_dev(port); > > err = mvpp2_bm_update_mtu(dev, mtu); > - if (!err) { > + if (err) { > + netdev_err(dev, "failed to change MTU\n"); > + /* Reconfigure BM to the original MTU */ > + mvpp2_bm_update_mtu(dev, dev->mtu); > + } else { > port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); > - goto out_start; > } > > - /* Reconfigure BM to the original MTU */ > - err = mvpp2_bm_update_mtu(dev, dev->mtu); > - if (err) > - goto log_error; > - > -out_start: > - mvpp2_start_dev(port); > - mvpp2_egress_enable(port); > - mvpp2_ingress_enable(port); > + if (running) { > + mvpp2_start_dev(port); > + mvpp2_egress_enable(port); > + mvpp2_ingress_enable(port); > + } > > - return 0; > -log_error: > - netdev_err(dev, "failed to change MTU\n"); > return err; > } > > -- > 2.21.0 >
On Fri, Jul 26, 2019 at 2:50 PM Antoine Tenart <antoine.tenart@bootlin.com> wrote: > > Hi Matteo, > > On Fri, Jul 26, 2019 at 01:19:31AM +0200, Matteo Croce wrote: > > The MTU change code can call napi_disable() with the device already down, > > leading to a deadlock. Also, lot of code is duplicated unnecessarily. > > > > Rework mvpp2_change_mtu() to avoid the deadlock and remove duplicated code. > > > > Signed-off-by: Matteo Croce <mcroce@redhat.com> > > As this is a fix sent to net, you could add a Fixes: tag. > > Otherwise this looks good, > Acked-by: Antoine Tenart <antoine.tenart@bootlin.com> > > Thanks! > Antoine > > > --- > > .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 41 ++++++------------- > > 1 file changed, 13 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > > index 2f7286bd203b..60eb98f99571 100644 > > --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > > +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c > > @@ -3612,6 +3612,7 @@ static int mvpp2_set_mac_address(struct net_device *dev, void *p) > > static int mvpp2_change_mtu(struct net_device *dev, int mtu) > > { > > struct mvpp2_port *port = netdev_priv(dev); > > + bool running = netif_running(dev); > > int err; > > > > if (!IS_ALIGNED(MVPP2_RX_PKT_SIZE(mtu), 8)) { > > @@ -3620,40 +3621,24 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu) > > mtu = ALIGN(MVPP2_RX_PKT_SIZE(mtu), 8); > > } > > > > - if (!netif_running(dev)) { > > - err = mvpp2_bm_update_mtu(dev, mtu); > > - if (!err) { > > - port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); > > - return 0; > > - } > > - > > - /* Reconfigure BM to the original MTU */ > > - err = mvpp2_bm_update_mtu(dev, dev->mtu); > > - if (err) > > - goto log_error; > > - } > > - > > - mvpp2_stop_dev(port); > > + if (running) > > + mvpp2_stop_dev(port); > > > > err = mvpp2_bm_update_mtu(dev, mtu); > > - if (!err) { > > + if (err) { > > + netdev_err(dev, "failed to change MTU\n"); > > + /* Reconfigure BM to the original MTU */ > > + mvpp2_bm_update_mtu(dev, dev->mtu); > > + } else { > > port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); > > - goto out_start; > > } > > > > - /* Reconfigure BM to the original MTU */ > > - err = mvpp2_bm_update_mtu(dev, dev->mtu); > > - if (err) > > - goto log_error; > > - > > -out_start: > > - mvpp2_start_dev(port); > > - mvpp2_egress_enable(port); > > - mvpp2_ingress_enable(port); > > + if (running) { > > + mvpp2_start_dev(port); > > + mvpp2_egress_enable(port); > > + mvpp2_ingress_enable(port); > > + } > > > > - return 0; > > -log_error: > > - netdev_err(dev, "failed to change MTU\n"); > > return err; > > } > > > > -- > > 2.21.0 > > > > -- > Antoine Ténart, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com It seems to me that the fixes tag should refer to the driver inclusion: Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
From: Matteo Croce <mcroce@redhat.com> Date: Fri, 26 Jul 2019 01:19:31 +0200 > The MTU change code can call napi_disable() with the device already down, > leading to a deadlock. Also, lot of code is duplicated unnecessarily. > > Rework mvpp2_change_mtu() to avoid the deadlock and remove duplicated code. > > Signed-off-by: Matteo Croce <mcroce@redhat.com> Please resubmit with the Fixes: tag. Please do not line break the Fixes: tag no matter how many characters it ends up being in total. Thanks.
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 2f7286bd203b..60eb98f99571 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3612,6 +3612,7 @@ static int mvpp2_set_mac_address(struct net_device *dev, void *p) static int mvpp2_change_mtu(struct net_device *dev, int mtu) { struct mvpp2_port *port = netdev_priv(dev); + bool running = netif_running(dev); int err; if (!IS_ALIGNED(MVPP2_RX_PKT_SIZE(mtu), 8)) { @@ -3620,40 +3621,24 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu) mtu = ALIGN(MVPP2_RX_PKT_SIZE(mtu), 8); } - if (!netif_running(dev)) { - err = mvpp2_bm_update_mtu(dev, mtu); - if (!err) { - port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); - return 0; - } - - /* Reconfigure BM to the original MTU */ - err = mvpp2_bm_update_mtu(dev, dev->mtu); - if (err) - goto log_error; - } - - mvpp2_stop_dev(port); + if (running) + mvpp2_stop_dev(port); err = mvpp2_bm_update_mtu(dev, mtu); - if (!err) { + if (err) { + netdev_err(dev, "failed to change MTU\n"); + /* Reconfigure BM to the original MTU */ + mvpp2_bm_update_mtu(dev, dev->mtu); + } else { port->pkt_size = MVPP2_RX_PKT_SIZE(mtu); - goto out_start; } - /* Reconfigure BM to the original MTU */ - err = mvpp2_bm_update_mtu(dev, dev->mtu); - if (err) - goto log_error; - -out_start: - mvpp2_start_dev(port); - mvpp2_egress_enable(port); - mvpp2_ingress_enable(port); + if (running) { + mvpp2_start_dev(port); + mvpp2_egress_enable(port); + mvpp2_ingress_enable(port); + } - return 0; -log_error: - netdev_err(dev, "failed to change MTU\n"); return err; }
The MTU change code can call napi_disable() with the device already down, leading to a deadlock. Also, lot of code is duplicated unnecessarily. Rework mvpp2_change_mtu() to avoid the deadlock and remove duplicated code. Signed-off-by: Matteo Croce <mcroce@redhat.com> --- .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 41 ++++++------------- 1 file changed, 13 insertions(+), 28 deletions(-)